Network processors that handle data received over a framed serial link, e.g., a T1 trunk, typically perform an aggregation of time-division multiplexed (TDM) timeslots. A timeslot configuration is used to determine which TDM timeslots from each trunk frame are to be combined into “channels”. The network processor also aggregates some number of frames of data for each channel, for example, a byte from the same timeslot in each of four frames for a 32-bit word. Each channel's data for a given frame may include “M” timeslots, where M is the channel size or number of timeslots used by that channel. The timeslot configuration enables up to N unique channels within a trunk, where N is the number of timeslots per frame on the trunk (e.g., 32 for E1, 24 for T1).
Such network processors require that the channels are “non-overlapping” (or non-interleaved), that is, that the timeslots assigned to one channel do not appear between timeslots belonging to another channel. For example, a configuration in which timeslots 0,1,2 belong to channel X and timeslots 3,4,5 belong to channel Y would be supported, while a configuration in which timeslots 0,2,4 belong to channel X and timeslots 1,3,5 belong to channel Y would not be supported.